Common end closures for beer and beverage containers have a central panel that has a frangible panel (sometimes called a “tear panel,” “opening panel,” or “pour panel”) defined by a score formed on the outer surface, the “consumer side,” of the end closure. Popular “ecology” can ends are designed to provide a way of opening the end by fracturing the scored metal of the panel, while not allowing separation of any parts of the end. For example, the most common such beverage container end has a tear panel that is retained to the end by a non-scored hinge region joining the tear panel to the remainder of the end, with a rivet to attach a leverage tab provided for opening the tear panel. This type of container end, typically called a “stay-on-tab” (“SOT”) end has a tear panel that is defined by an incomplete circular-shaped score, with the non-scored segment serving as the retaining fragment of metal at the hinge-line of the displacement of the tear panel.
The container is typically a drawn and ironed metal can, usually constructed from a thin plate of aluminum. End closures for such containers are also typically constructed from a cut-edge of thin plate of aluminum or steel, formed into a blank end, and manufactured into a finished end by a process often referred to as end conversion. These ends are formed in the process of first forming a cut-edge of thin metal, forming a blank end from the cut-edge, and converting the blank into an end closure which may be seamed onto a container. Although not presently a popular alternative, such containers and/or ends may be constructed of plastic material, with similar construction of non-detachable parts provided for openability.
These containers are typically filled with carbonated beverages that create a substantial pressure within the container. Upon opening the container, this pressure must be quickly and safely vented. For this reason can ends are constructed for venting or releasing the internal pressure of the container during the initial opening of the container.
When the tab is lifted, an upward force is placed on a rivet that attaches the tab to the end, and a downward force is placed on the tear panel. This causes an initial opening of the tear panel beneath the nose of the tab in an area referred to as the vent region of the can end. Further lifting of the tab causes the tear panel to separate progressively along the score.
Upon fracturing of the vent region, rapid disassociation of the tear panel from the end panel, or more simply, the “missiling” of the tear panel may occur. For this reason, some manufacturers place anti-missile features on the consumer side of the can end.
More recently, manufacturers have attempted to provide resealable beverage containers wherein the resealable closure cap seals a dispensing aperture rather than the SOT design described above. To date, these efforts have not been widely accepted as commercially viable. One reason for the lack of acceptance is the difficulty presented by the substantial pressure within the container that must be quickly and safely vented.
The present invention is provided to solve the problems discussed above and other problems, and to provide advantages and aspects not provided by prior resealable can end closures of this type. A full discussion of the features and advantages of the present invention is deferred to the following detailed description, which proceeds with reference to the accompanying drawings.